ROT2 command of IRIS

[highfnum]

What is rate that slits vibrated

[Merlin66]

John,
Around 30-40 oscillations per second is needed for persistence of vision, p 66-67.

[Merrill55]

Maybe,for visual using oscillations is 20-30 per second vibration and for graphical using is 5-10 per second.
For photo it need not make vibrate so fast. Conposite procedure is useful for smoothing.

[Wah]

Hi Merrill55,
I am sorry that the SLiM has some problem to process the avi files because it is using an external library to decode the avi format.
If you use the mono 8bit or 16bit SER file format to capture the video, it should be able to support without problem (I hope)
I was too lazy to implement the code for 16bit SER vertical mode, please make the spectral lines horizontally while using 16bit SER.
Also, using ROI function to reduce the video resolution can help improving the processing speed and also the capturing frame rate.
Thanks!

[Merrill55]

Thanks Wah.
I'm beginner in SHG. So I must learn more about dogital procedure.
ROi is helpful for me.
I tried Vdub and SLim recently.
I Try to more experience about DigitalSpectroheliograph.

Thank you.

[Merlin66]

Toshio,
You may find the new book "Imaging Sunlight -using a digital spectroheliograph" useful.
It has a whole chapter on the various processing software currently available and how to use them for the SHG.

[Merrill55]

Trial h-alpha photo.

Very poor image.

[Montana]

Wow! that's a great close up, well done

Alexandra

[Merrill55]

Thanks Alexandra.

I will try to get more detail the solar surface.

Toshio

[highfnum]

Toshio - do you know of any other SHG or SHS in Japan (amateur)

[Merrill55]

I know one amateur. His name is Takashi Sakae. He is a teacher of high school.

I don't know any other amateur without him.

[highfnum]

Very nice

Ken - guess you have to update total counter

[Merlin66]

John,
Already done!!
I'll look at translating the documents.

[Merrill55]

My Christmas solar image is as follows;
Somewhat blur image.

[Montana]

Wow!! some lovely filaments, well done and Merry Christmas!
Alexandra

[Merrill55]

Merry Christmas all.
Have a nice holy night !!

Toshio (a part of HYLOV P.233)

[highfnum]

Picture improved
Enjoy

[Merrill55]

Trial h-alpha photo by short SHG. 2016_12_31

[highfnum]

Much better
Focus improvement is noticeable

[Spectral Joe]

Yes, it's shaping up. I see two immediate issues. First, there's a lot of stray light. This can be due to misplaced reflection traps, but in your case it's likely back reflections from the binoviewer. Second, there is noticeable vignetting in the direction along the slit, usually the result of not having the telescope objective imaged onto the grating. It's a common problem, fixed by using a field lens at the entrance slit. Overall, though. this is a very good start.

[Montana]

This is a massive improvement, that is a tremendous image
Alexandra

[Merrill55]

Bartolick;

Yes,I should pay attention to stray light. I recognize it.
Littrow lens cause a strong ghost.(Acromatic lens cause four goast)
The binoviewer cause a strong ghost of the slit shape.
Therefore I block it using red filter (R64) in the lower part of the binoviewer.
When I use other wavelengths, the use of the color filter corresponding to each will be necessary.

The serious problem is not good quality collimator lens which light passes twice.
I must exchange on an apochromatic lens.
Probably I think that the image becomes a little sharper.

[Merrill55]

Hi all;
Recent my SHG image.
Low contrast !!

[Montana]

Very nice prom in the south east
Alexandra

[marktownley]

Very good!